Recently, radio frequency (high frequency) applications of magnetic elements have expanded in read/write heads, micro inductors, micro transformers, and the like. Accordingly, thin magnetic films having excellent high-frequency properties are required also in a GHz band, and thus, research and development relative to these have been actively carried out. In order to use a thin magnetic film in a radio frequency band, it is necessary to increase the electric resistance of the thin film to thereby reduce eddy-current loss and to heighten resonant frequency. As a method for heightening the resonant frequency, there are such methods as heightening an anisotropic magnetic field Hk or a saturation magnetization Ms, but to heighten the Hk and Ms at the same time is generally difficult, and is in a trade-off relation. However, in recent years, it has become possible to enhance a uniaxial magnetic anisotropy due to the shape effect of crystals by causing sputtered particles to enter and orient obliquely relative to a substrate by using a sputtering method or an ion beam method, and to heighten the Hk, too, while maintaining a high Ms.
The application range of the oblique deposition is expanding repeatedly, and as a production method of causing sputtered particles to enter obliquely relative to a substrate to thereby form an obliquely oriented film, there is a substrate-passing type deposition structure in which a substrate passes the front of a target carrying out a sputtering operation (Patent Document 1). Furthermore, there is also a method in which only a substrate holder is rotated and controlled to thereby cause a film to grow obliquely (Patent Document 2).
Moreover, there is a method utilizing the oblique deposition when forming an insulating thin film by plural ion beams (Patent Document 3). That is, Patent Document 3 discloses a method for depositing an insulating thin film on a magnetic head, the method being for forming evenly an insulating film on a large surface area. FIG. 10 is an outline view of a deposition apparatus disclosed in Patent Document 3. The deposition apparatus shown in FIG. 10 comprises a chamber 1011 for housing a first ion beam gun 1012, a second ion beam gun 1013, a target holder 1014, and a substrate support 1016.
The substrate support 1016 has a turn table 1016a rotatable about a shaft 1016b (about an axis 1021a), and a substrate-fitting table 1016c rotatable about an axis 1021b. On the substrate-supporting table 1016c, a substrate 1017, on which a target material is to be deposited, can be arranged. On the other hand, the target holder 1014 is configured so as to be swingable in an arrow direction 1022, and can be fitted with a target 1015.
The first ion beam gun 1012 is disposed so that an ion beam 1018 enters the target 1015, and the ion beam 1018 causes the target material to disperse from the target 1015 in random directions 1020. The second ion beam gun 1013 is disposed so that another ion beam 1019 enters the substrate 1017 in the deposition process.
The method disclosed in Patent Document 3 can attain an even film thickness on the substrate 1017 by rotating suitably the target holder 1014, the turn table 1016a and the substrate-fitting table 1016c in the above-described configuration.
[Patent Document 1] U.S. Pat. No. 6,818,961
[Patent Document 2] Japanese Patent Application Laid-Open Publication No. 06-144990
[Patent Document 3] Japanese Patent Application Laid-Open Publication No. 08-296042
[Patent Document 4] Japanese Patent Application Laid-Open Publication No. 11-283926